Welding in the World最新文献

{"title":"Surface pretreatment of 6063 aluminum alloy and strengthening mechanism of vacuum diffusion bonding joint","authors":"Jiafen Song,&nbsp;Lichi Ma,&nbsp;Yunjia Huang,&nbsp;Shiming Xu,&nbsp;Yu Peng,&nbsp;Jiangtao Xiong,&nbsp;Jinglong Li","doi":"10.1007/s40194-026-02372-8","DOIUrl":"10.1007/s40194-026-02372-8","url":null,"abstract":"<div><p>The diffusion bonding of 6063 aluminum alloy with surface pretreatment was carried out in this paper. The 6063 aluminum alloy (AA6063) is often used in the manufacture of micro-channel heat exchangers (PCHE). However, due to the existence of a stable surface oxide film (Al₂O₃) with a high melting point, which prevents the close contact of the surface to be bonded and the diffusion of atoms. This paper designed the acid and alkali washing cleaning before the bonding process. Three protection schemes were designed for the cleaned surface protection, namely, ethanol protection, α-terpineol surface protection, and magnesium powder terpineol mixed protection. The bonding temperature of diffusion bonding was 540 ~ 580 °C, the pressure was 4 MPa, and the bonding time was 120 min. The microstructure of the joint was studied by scanning electron microscopy. The mechanical properties of the joint were evaluated by a tensile test. The results show that with the optimal process of 570 °C–4 MPa–120 min, the α-terpineol-protected joint achieved a tensile strength of 113.3 MPa and an elongation of 28.1%. It provides a feasible design idea for the diffusion bonding of 6063 aluminum alloy.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 6","pages":"2495 - 2504"},"PeriodicalIF":2.5,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147985266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process optimization and microstructural–mechanical analysis of dissimilar ultrasonic welding of aluminum and nickel-coated copper","authors":"Vahid Allahverdizadeh,&nbsp;Rezvan Abedini","doi":"10.1007/s40194-026-02423-0","DOIUrl":"10.1007/s40194-026-02423-0","url":null,"abstract":"<div><p>The rapid development and production of electric vehicles, along with the growing demand for advanced energy storage systems such as modern batteries, have significantly increased the importance of ultrasonic metal welding as a joining method. In this study, dissimilar ultrasonic welding of aluminum alloy AA1050 and high-purity copper (99.9%) coated with nickel was investigated. The effects of key process parameters—welding time, pressure, and amplitude—on the mechanical strength of the joint were examined and optimized using design of experiments (DOE) and the response surface method (RSM). To evaluate the joint strength, tensile-shear tests were conducted, accompanied by microscopic examination of the weld cross-section and the fracture surfaces. The DOE results indicated that welding time, pressure, and the second-order term of ultrasonic amplitude are the most influential parameters positively affecting the joint strength. The maximum tensile shear strength obtained was 869.4 N. With an increase in welding time, the effective weld thickness improved significantly—from 55.2% for a 0.2-s weld time to 34% at 1 s. Microstructural analysis at the weld interface revealed that interfacial diffusion and mechanical interlocking are the dominant welding mechanisms. The effective thickness and bond density of weld were identified as the most critical microstructural factors influencing the joint strength. Moreover, compared to the direct welding of dissimilar aluminum and copper, the presence of the nickel coating enhanced the joint strength at shorter welding times and across a broader range of parameters—leading to an approximately 5.5% increase in maximum mechanical strength.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 11","pages":"5743 - 5765"},"PeriodicalIF":3.1,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of different fatigue assessment methods for HFMI-treated longitudinal stiffeners under variable amplitude loading","authors":"L. Wendler,&nbsp;T. Nitschke-Pagel,&nbsp;I. Engelhardt","doi":"10.1007/s40194-026-02427-w","DOIUrl":"10.1007/s40194-026-02427-w","url":null,"abstract":"<div><p>Due to the extensive research on High-Frequency Mechanical Impact (HFMI) treatment in recent years, regulations regarding HFMI treatment are increasingly being incorporated in the revision of design codes and recommendations. Generally, these trends promise a greater application of HFMI treatment in practice and therefore offer the potential of realising resource-efficient and durable lightweight constructions. However, the increasing number of guidelines is also accompanied by some differences regarding the assessment methods and the evaluation of the fatigue life of HFMI treated welds which may lead to divergent estimations of fatigue life. Therefore, this study analyses differences between the assessment methods, provided by current and upcoming design codes and recommendations for HFMI treated welds, specifically in terms of nominal and effective notch stress approach. Overall, the results indicate that current design rules lead to a conservative fatigue assessment, implying that the potential of an increased fatigue strength cannot be fully considered within the fatigue life estimation. This study primarily focuses on options of taking different R-ratios into account, as well as the impact of the intersection point of AW and HFMI S–N curve emphasising the assessment of variable amplitude loading. It is observed that particularly at R = − 1 the fatigue assessment tends to be overly conservative due to the inability to account for this effect. Additionally, the results suggest that neglecting the intersection point between AW and HFMI S–N curve may result in an even more conservative fatigue assessment, especially at higher stress ranges. The comparison of different fatigue assessment methods within this study focuses on current IIW-recommendations as well as the upcoming revised version of Eurocode. Applying different assessment methods reveals no significant differences in fatigue estimation, as conservative results were obtained for both guidelines considered in this study. The comparison is carried out based on fatigue test data on the example of the structural detail “longitudinal stiffener” under variable amplitude loading.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 5","pages":"2037 - 2060"},"PeriodicalIF":2.5,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40194-026-02427-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147727640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled thermal–mechanical analysis of laser beam-welded 316L stainless steel via finite element method","authors":"M. Zubairuddin,&nbsp;B. Yelamasetti,&nbsp;R. Ravikumar,&nbsp;Gaurang. R. Joshi,&nbsp;Vivek J. Pathak,&nbsp;R. K. Buddu,&nbsp;Dhanesh G. Mohan","doi":"10.1007/s40194-026-02413-2","DOIUrl":"10.1007/s40194-026-02413-2","url":null,"abstract":"<div><p> The present study examines the thermal–elastoplastic behaviour of SS 316L stainless steel welds during pulsed laser welding through combined experimental and numerical analysis. Initially, bead-on-plate experiments were performed with different heat inputs to determine the optimal condition for achieving full penetration. The identified optimal heat input was then applied to square butt joint welds to analyze thermal cycles, residual stresses, and distortions, as well as to guide heat source modelling. For finite element modelling (FEM) in SYSWELD, both conical and combined (conical plus ellipsoidal) heat source models were used to simulate the welding process and predict the resulting thermal–mechanical responses. Thermal cycles were recorded using surface-mounted thermocouples, vertical displacements were measured with an electronic height gauge, and residual stresses were evaluated via ultrasonic testing. Results showed that the combined heat source model predicted maximum temperatures within 4% of experimental values, whereas residual stresses and distortions were within 16–29% of measured values, demonstrating its superior accuracy in capturing weld-induced thermal and mechanical behaviour.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 11","pages":"5729 - 5742"},"PeriodicalIF":3.1,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the brazing process of TC4 titanium alloy/304 stainless steel and the effect of gap on braze joint performance","authors":"Shuang Xie,&nbsp;Guanyu Yao,&nbsp;Jianqiao Xiong,&nbsp;Jin Ouyang,&nbsp;Jingqing Chen,&nbsp;Hui Chen","doi":"10.1007/s40194-026-02424-z","DOIUrl":"10.1007/s40194-026-02424-z","url":null,"abstract":"<div><p>The joining of titanium alloys and stainless steels is critically required in aerospace and other fields, frequently accomplished through brazing. This paper investigates vacuum brazing of TC4 titanium alloy and 304 stainless steel using Ag70-Cu26-Ti4 filler metal. Through SEM/EDS, XRD characterization, and shear tests, the effects of process parameters on interfacial microstructure evolution and mechanical properties were analyzed. The filler metal’s fluidity at different gaps and its impact on joint strength were examined. Results demonstrate that the joint achieved optimal shear strength of 191 MPa at 830 °C/5 min, with appropriate reaction layer thickness and dispersed brittle Cu-Ti phases. Elevated temperature caused Cu-Ti phase coarsening throughout the brazing seam, reducing strength. At 0.21 mm gap, the filler metal showed optimum fluidity with 31 mm filling distance, yielding maximum shear strength of 127 MPa at 850 °C/5 min. Reaction layer growth kinetics revealed activation energies of 111.0 kJ·mol⁻¹ in Zone III (TC4 side) and 244.5 kJ·mol⁻¹ in Zone I (stainless steel side), confirming easier diffusion of Cu and Ti atoms in the titanium alloy. This study provides theoretical guidance for suppressing brittle phase formation and optimizing brazing gap design.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 6","pages":"2539 - 2553"},"PeriodicalIF":2.5,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147985210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the nano-mechanical properties and creep resistance of dissimilar AA7075/Ti-6Al-4 V weldments using a Cu interlayer in laser beam welding","authors":"Asim Iltaf,&nbsp;Shayan Dehghan,&nbsp;Noureddine Barka,&nbsp;Rafiq Ahmad","doi":"10.1007/s40194-026-02393-3","DOIUrl":"10.1007/s40194-026-02393-3","url":null,"abstract":"<div><p>Dissimilar laser welding of AA7075 aluminum and Ti-6Al-4 V titanium alloys is promising for lightweight structures, but the formation of brittle Ti/Al intermetallic compounds (IMCs) can degrade local mechanical integrity and creep resistance. This work evaluates whether introducing a copper (Cu) interlayer during laser beam welding can enhance the local nanomechanical response and room-temperature nanocreep behavior of AA7075/Ti-6Al-4 V joints. Butt welds were produced using a 380-µm Cu foil, and depth-sensing nanoindentation was applied to map nanohardness, elastic modulus, and indentation creep across the AA7075 heat-affected zone (HAZ), fusion zone (FZ), mix zone, and the Cu/Ti-6Al-4 V interface. Atomic force microscopy was used to characterize indentation-induced surface relief. The Cu interlayer increased nanohardness from 1.37 GPa in the AA7075 HAZ to 5.81 GPa at the Cu/Ti-6Al-4 V interface and increased elastic modulus from 64.1 to 73.2 GPa. The maximum creep displacement (~ 176 nm) occurred in the AA7075 HAZ with <i>n</i> ≈ 2.1, indicating grain-boundary-controlled creep, whereas the Cu/Ti-6Al-4 V interface showed the lowest displacement (~ 121 nm) and the highest stress exponent (<i>n</i> ≈ 3.2), consistent with dislocation-controlled creep. These observations together with microstructural analysis indicate that the Cu interlayer suppresses a continuous Ti/Al IMC layer and instead promotes a thin Cu-rich mix zone and refined interface grains, thereby raising local stiffness/hardness and shifting the dominant creep mechanism toward dislocation-controlled flow. Therefore, Cu-interlayer laser welding provides a microstructure-informed route to engineer Al/Ti joints with improved creep resistance at the critical interface.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 11","pages":"5715 - 5728"},"PeriodicalIF":3.1,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of hot isostatic pressing on the microstructure and mechanical properties of wide-gap brazed joints","authors":"Jie Liu,&nbsp;Mingsheng Wang,&nbsp;Xiangwei Jiang,&nbsp;Zishu Sun,&nbsp;Song Zhang,&nbsp;De Wang,&nbsp;Chunhua Zhang,&nbsp;Jiasheng Dong","doi":"10.1007/s40194-026-02430-1","DOIUrl":"10.1007/s40194-026-02430-1","url":null,"abstract":"<div><p>Wide-gap brazing (WGB) is an economically efficient and widely adopted technique for repairing superalloy components. However, controlling the formation of detrimental brittle intermetallic phases remains challenging even with optimized filler materials and brazing parameters. This study systematically investigates the effect of introducing hot isostatic pressing (HIP) as an intermediate process on the microstructure and mechanical properties of layered WGB CM247LC superalloy joints. Combining X-ray computed tomography (XCT), microstructural characterization, and mechanical testing, the results demonstrate that HIP treatment effectively eliminated internal porosity and reduced the void volume fraction from approximately 0.2% to 0.002%. Furthermore, HIP promoted boron diffusion, significantly reduced the amount and continuity of brittle boride phases. Mechanical tests confirmed that these microstructural improvements led to a remarkable enhancement in joint performance, including a 12-fold increase in stress rupture life at 900 °C/315 MPa and a 24% improvement in tensile strength. The findings underscore HIP’s critical role in achieving high-integrity repairs for wide-gap brazed superalloy joints.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 6","pages":"2555 - 2568"},"PeriodicalIF":2.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147985211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new approach for thermomechanical modeling of residual stresses in selective laser melting","authors":"Boussaâd Yacine Benchabane,&nbsp;Yacine Belkacemi,&nbsp;Hocine Kebir","doi":"10.1007/s40194-026-02411-4","DOIUrl":"10.1007/s40194-026-02411-4","url":null,"abstract":"<div><p> Residual stresses generated during selective laser melting (SLM) can severely affect the component’s performance. Correctly estimating such a defect prior to fabrication is therefore crucial. Our objective is to develop a finite element model with a new approach for simulating the laser-material interactions to accurately predict these stresses while keeping a reasonable computational time. To do so, we introduce the track discretization technique, which consists in defining the various tracks of the laser beam path and discretizing them to reproduce the scanning strategy. The existing layer-by-layer and track-by-track heating are also implemented. All three versions of the model employ a constant and uniform body heat flux. Their results are compared to those of the detailed simulation using the Goldak heat source. SLM of an AlSi10Mg square plate is studied for testing purposes. von Mises and normal stresses, <span>({sigma }_{11})</span> and <span>({sigma }_{22})</span>, are probed along specific paths to assess the efficiency of each approach. Heating entire layers was the fastest but the worst for predicting stress anisotropy. A more realistic representation of the scanning pattern by adding the various tracks and subdividing them enhances precision of the estimations. The trade-off between accuracy and rapidity of execution was obtained with three track subdivisions. In this case, the estimates were consistent with the detailed simulation results, and the errors were, on average, 20–30% lower than those of the more simplified versions. The duration of the simulation was 335 min vs 1297 min with the detailed procedure, which corresponds to a significant gain of 74.2%.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 11","pages":"5699 - 5714"},"PeriodicalIF":3.1,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing a methodology to assess liquid metal embrittlement impact on the fatigue life of resistance spot welds","authors":"M. Ullrich,&nbsp;S. Jüttner","doi":"10.1007/s40194-026-02421-2","DOIUrl":"10.1007/s40194-026-02421-2","url":null,"abstract":"<div><p>Third-generation advanced high-strength steels (3G AHSS) are widely used in automotive applications due to their exceptional mechanical properties, including high tensile strength and fracture toughness. Resistance spot welding is the dominant joining process for these steels in the body-in-white production due to the high productivity and automation capability. Though exhibiting satisfying welding current ranges, AHSS can have the downside of showing zinc-induced liquid metal embrittlement (Zn-LME), a phenomenon in which the exposure of the susceptible base material to the liquid zinc coating in combination with the induced tensile stresses during resistance spot welding can lead to cracking of varying severity. The presence of zinc-induced LME cracks can result in an unexpected failure of the component due to potential premature crack initiation and propagation under a mechanical load. While extensive research has been conducted on the effects of LME on static mechanical properties such as tensile strength and fracture toughness, its impact on fatigue life—a critical factor in the automotive application—remains less well understood. Fatigue failure can occur earlier as the presence of LME can accelerate the crack growth under cyclic loading. Understanding the interplay between LME-induced cracks formed during resistance spot welding and fatigue behavior is essential for improving the reliability and widening the application field of 3G AHSS. This study, which is the first part of a larger investigation, is aimed at developing a methodology for analyzing the influence of zinc-induced LME on the fatigue life of third-generation advanced high-strength steels (3G AHSS), focusing on the fatigue crack initiation and propagation mechanism under cyclic loading. To achieve this, LME cracks were generated via the usage of a decreasing electrode force profile and the reproducibility was investigated. The LME crack surface was investigated with stereo and scanning electron microscopy. The fatigue test for a specimen with severe LME cracking was monitored via digital image correlation (DIC), which enabled the evaluation of critical areas. The derived methodology serves as a guideline for quantifying the influence on LME cracks on the fatigue life and thereby assisting the development process of new materials and parts. In upcoming investigations, the methodology will be used to evaluate the influence of specific LME crack sizes and types.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 7","pages":"3141 - 3152"},"PeriodicalIF":3.1,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40194-026-02421-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148261967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of microstructure changes on the elastoplastic behavior in cross-wire welding using the finite element method","authors":"Muhammed Turan Aslan,&nbsp;Bahattin Kanber","doi":"10.1007/s40194-026-02426-x","DOIUrl":"10.1007/s40194-026-02426-x","url":null,"abstract":"<div><p>The elastoplastic behavior of dual-phase wires was investigated using both experimental methods and the explicit dynamic finite element with Johnson–Cook material model after resistance spot welding. The welded region was examined in detail using a scanning electron microscope, revealing three distinct regions: the welded zone, the heat-affected zone, and the unaffected zone. The breakage distance and displacements of the cross welded wire under load were studied for various alignment angles, electrode sizes, and wire diameters. Increasing the electrode diameter reduces the weld area’s deformation capacity by enlarging the brittle volume. At the highest wire diameter, as the electrode diameter increases, the elongation values decrease by 33.3%, 18.1%, and 7.1% for 0°, 45°, and 90°, respectively. However, due to the increase in wire diameter, the bending stress also increases, causing breakage in the WZ. The distance of the breakage is directly related to the ratio of the welding surface and the cross-sectional area of the wire. During tensile testing, the <span>({A}_{n}/{A}_{tr})</span> ratio is always below one, and damage occurs in the transition zone. In cross-tensile testing, the area ratio is above one, and rupture can occur in the welded zone, depending on the amount of bending stress.</p></div>","PeriodicalId":809,"journal":{"name":"Welding in the World","volume":"70 11","pages":"5679 - 5697"},"PeriodicalIF":3.1,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s40194-026-02426-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}